The look comes mainly from light direction, not lots of gear. In the example, the subject is lit from above and slightly in front, using what appears to be one main light. That high angle creates shadows across the abs and chest, which makes muscle definition stand out.

Try this:

• Use one light first as the key light.
• Place it directly above you, or slightly in front of your face/chest line.
• Keep the background dark and stand under the light.
• Raise the light as high as possible. If it’s too low, your shoulders will be much brighter than your abs.
• A smaller, less-diffused source gives crisper shadows; a softbox will still work, but harder light usually emphasizes definition more.

Your LEDs may be a limitation. If the light is high enough for even coverage, it may not be very bright, so expect longer exposures and use a tripod/self-timer.

The reflector or second light should be used very sparingly, if at all, since strong fill would reduce the sculpted look.

For the body look itself: flex during the shot, and a slight sheen (like oil) can help highlights and definition show more clearly.